How to Build a Homemade Theremin Using Basic Electronic Components


A theremin is an electronic musical instrument that is played without physical contact. Instead, the musician controls pitch and volume by moving their hands in proximity to two antennae. Theremins produce an eerie, wavering sound that has been used in many 1950s science fiction films.

Building your own theremin at home can be a fun electronics project that allows you to explore radio frequencies and analog circuitry. With just a few basic components, I was able to assemble a simple, functional theremin using tutorials I found online. In this article, I will walk through the step-by-step process I used to build a homemade theremin using basic electronic parts.

Gather the Required Components

The simplest theremin circuits can be built using just a handful of parts:

For a simple theremin, this is all you need! Additionally, a solder-able breadboard and various wires are necessary to connect it all together.

Construct the Pitch Control Circuitry

The pitch antenna needs circuitry that converts the hand movements into electrical signals that control the oscillator's pitch. Here are the steps I took:

The pitch circuitry has to be tuned carefully to sweep through the full melodic range you want. Trying different resistor and capacitor values helps dial in the proper range.

Construct the Volume Control Circuitry

The volume antenna needs circuitry that converts hand movements into electrical signals that control the amplifier's gain. Here is how I built mine:

The volume circuit should allow the theremin to be turned down completely when your hand is farthest from the antenna. Move your hand closer until the maximum volume is reached.

Combine the Oscillator and Amplifier Circuits

The last step is to connect the pitch control circuitry to the oscillator and connect the oscillator's output to the audio amplifier:

Once everything is connected, you should have a working theremin! Adjusting the component values and antenna positions can fine tune the pitch range and volume response.

Refinements for Better Performance

Here are some additional steps you can take to improve your homemade theremin:

With some tweaking and refinement, you can build a nice sounding theremin using basic components and a bit of electronics knowledge. Just take it step-by-step. Soon you'll be making eerie sci-fi music!